[cfe-dev] What's the rationale to continue declare compatibility with GCC 4.2.1?

[Simon Atanasyan via cfe-dev]

Hi,

Recently I get a request to implement in Clang a MIPS-related feature
which exists in GCC pre 4.4 and removed in later versions. There is a
rationale behind such strange request -- third-party software checks a
compiler's compatibility using __GNUC__,__GNUC_MINOR__ macros and
selects code dedicated for obsoleted version of GCC.

As to me I would use for __GNUC__,__GNUC_MINOR__,__GNUC_PATCHLEVEL__
macros defined in the InitializePredefinedMacros function the same
values as a minimal GCC version required for building LLVM/Clang [1].
Now it's 5.1.0.

Is there any rationale to continue declare compatibility with old GCC 4.2.1?

[1] https://llvm.org/docs/GettingStarted.html#software

-- 
Simon Atanasyan